How Much Energy Does an Electron Need to Tunnel Through a Barrier?

tricky1
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Homework Statement


An electron approaches a potential barrier 10eV high and 0.5nm wide. If the electron has a 1%chance of tunneling through, what must be its energy?


Homework Equations


Transmission probability = [C/A]^2= [ 1 + (U^2 sinh^2(mu alpha))/(4E(U-E))]^-1


where U=potential=10eV
E=energy of electron
mu=sqrt(2m(U-E)/hbar^2)
alpha = width of box = 0.5 nm


The Attempt at a Solution




I've substituted everything in and fiddled for ages but I really can't rearrange to make E the subject of this formula. can anyone help?
 
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And have you considered the possiblity to solve this numerically?
 
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